Australian filmmaker Warwick Thornton came to worldwide attention when he won best first film at the 2009 Cannes Film Festival for the bittersweet, outback romance Samson and Delilah.

Since then he's made smaller films, including last year's documentary about the Southern Cross as contested national symbol, We Don't Need a Map, and worked as a cinematographer on other film projects.

But it's taken him until now to return to a bigger canvas, on a narrative feature as ambitious as his first.

Sweet Country — a film that competed at last year's Venice Film Festival where it won a special jury prize — sees him tackle the Western, a genre well suited to examining issues of race and colonisation.

Returning to the ochre-coloured, scrub-flecked expanses around Alice Springs where he shot Samson and Delilah, he tells the story of an Aboriginal stockman who kills a white landowner in self-defence.

He contrasts a John Ford-inspired vision of frontier settlers sitting in the cool shadow of wooden huts with the squalid conditions of the local Indigenous people, routinely treated as nothing more than slaves. Children are chained up, men are beaten, women raped.

Editor Nick Myers strategically places flashbacks and flash-forwards that offer glimpses of personal traumas or future misfortunes, encouraging us to sympathise with even the most nasty villains.

We learn that the dead man, Harry March (a well-cast Ewen Leslie, despite a distractingly anachronistic accent), is a returned WWI soldier so brutalised by his experiences on the Western Front he drinks himself into a stupor each night.

And even the hard-bitten town cop (Bryan Brown) is given a tender side, depicted in bed with his lover (Anni Finsterer), a single mother who runs the pub.

Alongside the established cast — who also include Sam Neill as a naive but sincere Christian and an excellent Thomas M Wright as a station owner who jealously guards his crop of watermelons — Thornton places a series of Indigenous newcomers.

The two standouts are Gibson John, who plays station hand and tracker Archie, and Hamilton Morris as the killer Sam Kelly.

The surname is no accident, as we discover in a later scene where an outdoor projection of The True History of the Kelly Gang makes the none-too subtle but important point that Australians idolise white outlaws and demonise black ones.

Hamilton gives Sam the quiet, forlorn dignity of a tragic hero, and it anchors the film.

When he goes bush with his wife (Natassia Gorey Furber), the couple manage to dodge the posse sent to capture them, but the Indigenous people they encounter living in country prove just as hostile. It's a journey from frypan to fire.

The fact all this happens in 1929 — making it quite late for a Western and uncomfortably recent for Australian audiences — is telling.

The script, written by Steven McGregor and co-producer David Tranter, is a deliberate critique of modernity in full swing, at a time when the mechanised horror of The Great War has made monsters of men like Harry March.

The idea of this modernity as a powerful force sweeping across the land, replacing traditional culture with ideas as incongruous as watermelons in the desert, suggests the characters are pawns in a historical upheaval beyond their control.

But one criticism of Thornton's direction is that it doesn't quite rise to the dynamism of these tensions, especially when they erupt into armed confrontations between opposing groups harbouring distinct world views.

He has made a reflective, often beautiful film, though not one that could be defined as Slow Cinema, which has become almost a sub-genre in its own right on the film festival circuit.

The script calls for more brisk direction at times, and even a sense of humour (recurring gag has Brown stepping in whenever he sees someone make eyes at his lover across the bar), but Thornton's timing is less assured in these moments.